Secured criminal to be released (7)
I believe the answer is:
rescued
'be released' is the definition.
(thesaurus)
'secured criminal' is the wordplay.
'criminal' is an anagram indicator.
'secured' is an anagram of 'RESCUED'.
'to' acts as a link.
(Other definitions for rescued that I've seen before include "Saved (from danger)" , "Extricated" , "set free" , "Secured (anag.)" , "Saved from - seducer (anag)" .)